This book is a collection of documents, letters, and memoranda about atomic energy written by Leo Szilard. The documents, presented in English in chronological order, show the birth and growth of the atomic age from the perspective of the man who first conceived of how to construct an A-bomb. The book is a window into the written thoughts and deeds of an atomic pioneer and a highly opinionated individual. It reveals Szilard’s passionate efforts to beat the Nazis in the race for the atomic bomb, followed an equally passionate effort to prevent atomic attacks against Japan in August of 1945. Szilard’s ideas for an elite international organization for peace called Der Bund are presented in a draft proposal for the organization. The documents give an account not only of Szilard’s life, but an expert’s view on the early stages of atomic development.